1. Field of the Invention
The present invention relates to a rotating actuator having a rotatably mounted control shaft and an activatable mechanical stop device for generating a stop to limit the rotation of the control shaft in one or the other direction of rotation, and with an angle detection device for detecting a rotation of the control shaft.
2. Background Art
Rotating actuators are used, for example, in data input devices, in which the cursor can be controlled in various menu levels by turning the rotating actuator and, if necessary, by pressing or swiveling said rotating actuator. For example, such a rotating actuator can be part of a so-called joystick.
One such rotating actuator is known from DE 197 12 049 A1. In this previously known rotating actuator, the gearing of a device for generating a haptic interface is coupled with the control shaft. This device is an electric motor which, when correspondingly actuated, exposes the control shaft to a torque opposite the rotation of the control shaft. Various haptic interfaces can be provided depending on the triggering or activation of the electric motor both in terms of the current intensity acting on the electric motor and as a function of the current rotational angle position of the control shaft. An angle detection device is allocated to the rotating actuator to determine the current rotational angle position.
The rotating actuator can also be operated without triggering the electric motor, and hence without any haptic interface to effect the rotation. Therefore, it is possible to operate the same rotating actuator both without and with a predetermined haptic interface or with varying haptic interfaces as a function of the respective mode of the rotating actuator.
This is advantageous relative to those rotating actuators having a haptic interface-generating device that resembles a mechanical latch with a latching cam plate and one or more latching elements that engage in the latching cam plate to generate a haptic interface when turning the handle. In these mechanical haptic interface-generating devices, the haptic interface cannot be enabled or disabled and, in particular, the haptic interface also cannot be reversed.
The rotating actuator known from this document also makes it possible to simulate an end stop by appropriately supplying current to the electric motor. However, the disadvantage to this configuration is that simulating an end stop in this rotating actuator not only results in a high current consumption, but that the counteracting force provided by the electric motor to simulate the end stop can also be surmounted. Providing the user with an end stop that cannot be so easily surmounted would require that appropriately conceived electrical and electronic components be made available, something which is unfeasible, at least in the automotive industry. In addition, the current required for this purpose is sometimes not always available in a motor vehicle, for example.
DE 196 46 226 A1 discloses another rotating actuator having a stop device that can be enabled and disabled. The control shaft is rigidly connected to a wheel provided with pockets in which the ball of a latching device engages, so that the wheel is latched and turned. A compression spring acts on the ball, and the spring is also arranged so that it is acted on by an electromagnet, with which the spring bias acting on the ball can be adjusted. The electromagnet itself rests against an abutment that is fixed relative to the control shaft. This abutment is situated radially to the control shaft. This stop device can be set in such a way that the electromagnet moves the spring to a blocking position, as a result of which the ball engages in a pocket of the wheel allocated to the control shaft like a bolt and blocks rotation. The ball is then held in such a pocket in a precisely form-fitting manner.
The perceived disadvantage to this stop device that acts mechanically on the control shaft is that a stop can only be established in those positions of the wheel with its pockets relative to the ball in which the ball can engage in a pocket of the wheel. Therefore, a stop cannot be produced in intermediate positions. In order to again disable the enabled stop device that impedes the rotation of the control shaft so that the control shaft can be turned once more, and hence actuated, the electromagnet must be supplied with less or no current beforehand via additional actuation, thereby making it possible to further latch and turn the control shaft. It is inadvisable to perform such an additional, active operation.